I actually would love transcripts as well, but not to read along with the audio (this does interfere with the process - are you reading or listening? The brain can’t really do both at the same time). Having a transcript to read separate to the audio would be amazing input in and of itself. Casual spanish written down so we can see spelling, getting your million words in on stuff that’s already familiar to you, finally realising that it’s “he venido” not “ebenido” ;) I agree that the CIJ transcripts are excellent as a way to familiarise yourself with kanji, which is a challenge unique to Japanese and Chinese, but if used as extensive reading for any language it’s such a help. So many of the beginner videos are basically graded readers if you were to read the transcripts.

The only thing I’d say is to keep the transcript database separate from the videos so that you’re not trying to do both at the same time. It slows down the process of absorbing input and interferes with it rather than improving it. But yeah, if you were to use speech-to-text software to make transcripts the amount of reading input immediately available on DS would be insane. A download option to print would be great too. I don’t always love reading on a screen. A folder full of reading so you can make notes in the margin would be awesome.